The invention relates to an ophthalmodynamometer.
Ophthalmodynamometry in medicine is the measurement of the blood pressure on the eye. The blood pressure is measured without bleeding. According to the principle generally known for this purpose, the extravasal tissue pressure is continuously increased until as a result of relief of the vascular wall when the diastolic or minimum blood pressure is exceeded the blood vessel intermittently collapses, and when the systolic or maximum blood pressure is exceeded the blood vessel remains continuously closed. Ophthalmodynamometry is both time-consuming and personnel-intensive since to date at least two specialists were necessary to perform it, of which one operated the instruments for changing the intraocular pressure, and the other observed the vascular pulsations on the ocular fundus by indirect ophthalmoscopy.
FR 1 035 662 or EP 0 327 693 A1 disclose means for performing ophthalmodynamometry which comprise means for pressure generation, such as a contact body for applying pressure to an eye to be examined and for increasing the internal ocular pressure, and pressure detection means. In both publications a separately and specially designed contact body is used. This contact body is made roughly cylindrical; illumination is effected through it using a slit lamp, condenser lens system and partially transparent mirror, and observation optics are assigned for the examination. The hardware of this system is very complex and requires extensive experience when it is used for eye examination. Furthermore, the contact body is made such that light reflection on the surface of the cornea is largely eliminated. Furthermore, examination of the ocular fundus is possible only in the rotationally-symmetrical concave contact areas of the contact body with the cornea of the eye to be examined, so that only the central area of the ocular fundus can be viewed, while the retinal periphery cannot be acquired during the examination. The surface of the contact body away from the eye is flat and provided with an antireflection layer. Furthermore this surface is matched to the optical requirements for illumination and examination of the ocular fundus. The pressure applied via the contact body during ophthalmodynamometry is acquired via an opening closed with a membrane in the center of the cornea via an incompressible fluid as the pressure sensor. Thus the contact body also has a special configuration in that on the one hand it has a membrane and on the other a space which is sealed hermetically tight and which is filled with an incompressible fluid. Thus the pressure detection means is very complex both in terms of design and hardware.